Process of making herbicidal composition of matter



Patented Oct. 21, 1952 UNITED "STATES {PATENT jOFFICE H i N 2,614,919 VI PROCESS OF MAKING HERBICIDAL "CQMBOSITIONDF MATTER john CIR. Warrenand Frederick J. Hager,

, Elmira, Ontario, Canada, assignors to United Y States Rubber Company,New York, N. Yg, a

corporation of New Jers ey No Drawing. Application March 28, 1951,Serial No. 218,098 .1.

Jl i This invention relates to improvements in making a composition ofmatter containing an ester of an aryloxyacetic acid and a surfaceactiveand emulsifying agent therefor. More particularly, it relates to animproved process which comprises effecting the esterification of anaryloxyacetic acid with an alcohol and thereafter forming in situ asurface activeagent and emulsifier which is present during furtherformulation and is available during and after admixture of, theifinalformulation with water or with ,oil to give a water emulsion or an oilsolution which contains the ester of the, aryloxyacetic acid; and thesurface active agent. Still more particularly, it relates to a novelandimproved process in which a single material performs a dual ,role,serving as a highly effective catalystflduring the esterification andbeing thereafter neutralized withian or: ganic amine to form in situ ahigh effective sur face active, wetting, dispersing and emulsifyingagent which is subsequently available to perform these functions.

This invention is particularly applicable in the manufacture of thoseesters of aryloxyacetic acids which are useful for either plant growthregulating or weed-killing. For example, it is customary to market aconcentrate of such esters, such concentrate also containing a suitableproportion of a surface active agent or emulsifier and being dilutedwith a suitable proportion of water or oil in the field to make thefinal spray emulsion or solution which is applied to the plants, weeds,shrubs or trees.

Prior to the present invention, itwas customary to esterifyaryloxyacetic acids by using, when necessary, an acid t'ypified bysulfuric acid,

benzene sulfonic acid, p-toluene sulfonic. acid, pchlorobenzene sulfonicacid, alkane sulfonic acids such as ethane sulfonic acid, and the like,or inorganic salts of an acidic nature such as sodium acid sulfate, asan esterification catalyst. Upon completion of esterification, if theresidual catalyst was not removedit generally provided a source ofdecomposition of the ester product, during storage or furtherprocessing, with resulting instability. Consequently, the catalyst wasremoved as completely as possible after esterification by distilling theester or by water-washing or by filtration of the crude ester-afterneutralizing the catalyst when necessary. The acid catalyst wasneutralized with alkaline materials, such as sodium carbonate, sodiumbicarbonate, calcium hydroxide and calcium carbonate. However, removalof the catalyst was costly and complicated and was attendedby a markedloss in is Clai s. (01.71- .23)

yield. Furthermore, the salts formed upon neu tralization of the acidcatalysthad to be removed before further formulation; such removal wherethe-salts were in solution in the ester, was accomplished bywater-washing which entailed further expense and considerabledecomposition, and

in addition necessitated subsequent dehydration of the water-washedester as by distillation which is costly; in the case of insoluble saltssuch as were usually formed when calcium-containing alkaline materialswere employed for neutralization, an expensive and troublesomefiltration was required to effect removal of such salts.

In many cases, especially Where the ester is to be applied ultimately inthe form of a dilute water emulsion or, oil solution to plants, it ishighly desirable to incorporate a surface active, Wetting, dispersing oremulsifying agent with the ester, preferably during preparation of theformulation which is marketed. I-Ieretofore, all of such surface active,wetting, dispersing or emulsifying agent was a preformed materialincorporated with the purifiedester.

The principal object of the present invention is to overcome thedisadvantages of the prior practice outlined above. Another object is toprovide a novel and highly improved process, whereby one material servesboth as the esterification catalyst and as the basis of a considerableportion or all of the surface active agent, thereby simplifying thepreparation and reducing the cost and in addition giving a stable esterproduct forformulation. Another object is to provide anesterificationcatalyst which is catalytically of the same, order of activity assulfuric acid, benzene sulfonic acid and the alkane sulfonic acids andyet which is sufficientlymild as'to not catalyze decomposition in manyinstances where other catalysts would do so. The esterification catalystused in our invention is in a simple and effective manner convertedafter esterification is complete to a highly effective surface activeagent. Numerous other objects ofthepresent invention will be apparent tothose skilled in the ar i i The present invention is based upon ourdiscovery that the foregoing objects can be readily attained bycarryingout the esterification of the aryloxyacetic acid with the alcoholubyusing an alkyl-substituted aryl sulfonic acid as the esterificationcatalyst, and subsequently neutralizing the alkyl-substituted arylsulfonic acid with an organic amine whereby there is formedgin situ anamine salt of the alkyl-substituted aryl sulfonic acid which functionsas a; surface active,

- properties to any substantial extent.

wetting, dispersing or emulsifying agent when the resulting mixture isemployed, usually by further formulation and often ultimate admixturewith water or oil in the field to give the finalsprayemulsioneorsolution. Thus the alkyl-substituted aryr sulfonic acidfunctions in-a dual role, serving as a highly active yet mild (in thesense that it does not causeundesirable decomposition reactions to takeplace) esterification catalyst and being subsequently converted-mysimple neutralization with the organic amine to an effective surfaceactive or' like'ag'ent.

The alkyl side chain in 'theralkyl-substituted acetic acids and monoanddi-chlorotoloxyacetic aryl sulfonic acid can vary in length quite widely1 but, should contain'at least ten carbon atoms.

As is well-known in the art, the;propertie's oflthe salts of suchsulfonic acids vary with the number of carbon atomsin the alkyl sidechain; In the practice of the present invention we prefer'to employthose alkyl-substituted aryl sulfonic acids wherein thealkyrsideeha-inis "derived froin rela t'ively dong, straight-chain or branched chainparaffin hydrocarbons especially kerosene; and wherein the aryl group is'derived' from aromatic hydrocarbons typified by benzene,'-toluene,'xylene or--naphthalene;-these sulfoni'c acids being typi fled-by -kerylbenzene-sulfonic acidkeryl toluene sulfonic acid,kerylxylene'sulfohic-acid and keryl naphthalene-sulfonic acid. is-well-knownin the arty'the term 'keryP- denotes-a mixture of alkyl-side-chains ofdength -ranging from G12 to C16 and derived from 'a highlysaturated-kerosene of paraflinic nature, Kery'l benzene is made-zbychlorinating such "a kerosene to produce" predominatelythe'monochlorin'ated product which is then condensed with benzeneinatypical Friedel- Crafts reaction usihg aluminum chloride asthecatalyst. "The average molecular-weight of keryl benzene is 260 to-270lOur invention is particularlyuseful in making those" esters of-a'ry-loxyacetic acids which are effective plant growth regulators orweed-killers. Generally speaking, the aryloxyacetic acids used in"practicing our invention are members of the group consisting ofpheno'xyae'etic and naphthoxyacetic -'-acids and their nuolearly substitl ited derivatives wherein the substituents (on the phenyl ornaphthyll are halogen or are alkyl radicals, especially lOW'I' alkyliadi'alsr It is pointed out that-not allof such acids'nece'ssarily haveplant growth --regulat1ng or :weedekilling However, our invention canoeemployed to produce esters of V aryloxyacetic acids which :are of littleor no value :for :plant :growth regulating .or weedkilling purposes butwhich are useful: for: other purposes inwhichanester containing asurface active or like agent is desired, .as for example-tiercommingling with-a plasticmaterial, e. g.,-polyacids which have plantgrowth regulating or 'w'ee'dkillin'g action. example of 1a,monochlorotoloxyacetic acid having weed 'kill'ing action is2-methyl-4-chlorophenoxyacetic acid.

As the alcohol, we can use any aliphatic or 1alicyclic,-.alcohol-capable of esterifying the aryloxyaceticpiacid'. Thealcohol can be monohydric or polyhydric and it can contain etherlinkages -01"other'ilnkages or*substituent groups which donotinterferewith the esterification or with I "thedesiredactionof theester, e. g., plant growth regulating'weed killing or plasticization ofresins V l l ;:or..the like. .pEiam'ples' are any of the alkanols'ranging from 1 to 20 or even more carbon atoms per molecule, such'asmethyl, ethyl, n-propyl, isopropyl; 'n-butyl, isobutyl, n-amyl, isoamyl,hexyl, heptyl, octyl, nonyl, decyl, and dodecyl alcohols, -'ete.-';unsaturated alcohols such asallyl alcohol; alicycli'e 'aleoholssuchas'cyclo entanol and cyelehexenol; 'polyhydric -alcohols'sii'ch as causethey aremore diflicult ingeneralto est-eriiy since they decompose onheatingzin: the presence of -aci'ds' -su flicient1y :strong to act "ascatalysts and because incompleteesterifioation :results.

I In practicing our invention,we usually-employ the alkyl-substitutedzaryl .sulfonie 1 acid in :an amount ranging'from-0m5 to 15'% or evenhigher, these percehtagesilbeing by weight based onithe theoretical.fweight of the-ester-produced. .L'I'h'e reactiongis usually carried tosubstantialtcomple tion, that is untillthe amount :of 'GStBYJifOlIfiBdisasub'stantially" sa'y 98+l00:%', of. theoretical based zupon the;aryloxyacetic -:acid whichxisxusui ally employed Ina-molar :deficiencyrelative tozthe alcohol. llfia lcatalystawere not.:used, the extentrofesteriflcation of thearyloxyaceticlacidwould1foe much :less than :when;the iicatalyst .is used. "In many:cases particugrlylinl the case:of?thelower boilingialcohols, at: least about'l20 molar excess of;the:.alcohol iover rthe;aryloxyacetic acid. (i.-;.e., at least about5.1.2 ,:alcohol :groups :per carbonyl group) is employed,-theiexcessfalcohol ibeingme covered -from' theester product by simple orvac uum 'distillation and:beingreeused intthe iprocess. Whether simple:or vacuum distillation is used wilhdepenwen the alcoholand the ester.The same distillation 1 can -eonveniently serve to 'i' moveenv excess(if-Err extraneous water-entrain ing agent in the reaction'rniiiiture. I

In 'the ease of -the hieher -boiling alcohols, it is-possible to:obtainfairly complete'esteriflcation using 5=% 'exeessalcehor or even less.Often, particulariyiin the ease e'tthe lower boiling alcohols, it isexpedient to use more than -20 excess e1- cohol especially when anextraneous entrai'riing agent for the water -i's not' used Suchexcessalcohol can often-serve as'a water-entraining agent,

The .amo'umzoi catalyst :used can varynvv'lthln homogeneous solutionwillthe range given above, depending upon mer ersamount of -'surfaceactive or tors including the like agent desire'd'tobe formed in-sitii bymeans of our invention; the skill of the-formulato'rand the requirementsofthe from 1 to 2% ofthesulfonic'acid based on "ester product. However,thergn ay be cases where a considerable excess is used insofar ascatalytic ed, sufch excess notjliindering activity is come catalyticeffect to any-"sutstanuai degree and e 1 distillation being carriedout-eitheiyatnormals'or esterifying mixture to removethewater continuously. As previouslyindicated, insomecases the itself can serve astheflWater-entraining' alcohol agent. 7

Whenesterification is complete; the reaction] mixture is treated in anobvious "manner to recover therefrom any materials other than the esterproduct and the catalyst.

The mixture of the ester and the" catalyst .thus

obtained 1s ncw commingledvlith the organic amount sufiicientto;substantially completely neutralize the catalyst.

aminewhich is employed in Any free aryloxyacetic acid present can be partially or completely neutralized by using an appropriate additionalamount of the organicamine. Typically the organic amineis; added inamount suificient to bring the pHof' the m'i x'ture to from 4 to 7. Thisstepofour'invention is ee.

This water gener distillation as the 'I'he mixture which is neutralizedwiththe organic amine should consist of the ester and the long chainalkyl 'arylsulfonic acid. Water is desirably completely or substantiallyabsentfrom the mixture so that a be'obtain'ed. I'his',o f course, isdesirable forsubsequent formulation and minimizes corrosion andhydrolysis. The or:

groupto the nitrile. group and then reducing the p m ry amine group: Qthr-..aminesssuchaas formulation to be madegf Optimum catalytic activityis generally foundat 1 corresponding proportion} 1t is preferred to thewater of-r'e eke 'rl manner concomitantly with the esterilficatiioh, asby ordi-f nary distillation orezeoue ie-wannabe; the

. d b in anysuitable way effecting intimate "intermix prior to theneutraliza fatty acids by can:

nitrile grouiitoLthe;

, as "octy1amine I and Arrneen C 520" reduced pressure depending uponconditions. We; often prefer to carry out the esterifictaion in-ethepresence of an inert entraining -agent for'the war-x ter of reactionandto. azeotropicallydistill the.

methoiiy propylamine, octylamine, and cycloheib ylamine' can be used inour invention.

The organic aminescan be selected-from the.

group of amines havingthe general formula where X, Y and Z are eachselected from the groupfconsistingfofhydrogen, alkyl,hydroxyalkylfalkoizy and c'ycloalkyl, not more" than two of the-threegroup's X;--Y and Z being hydrogen,

hydrogen.

oils used in formulations; the higher amines such are generally betterthan the: 1ower amines; such higher amines are excellent for purposesactive agent; however, the salts of alkylyaryl'fsiilfonic acid formed bysuch higher amines,- "though surfaceactive, are I diific'ultlysoluble inwater, and so do not appreciably assist in speed of emulsijficationinwater though they may stab'ilizethe emulsion.

The amine salt of the long chain alkyl aryl sulfonic acid isdissolved inthe ester, goingfiinto'f formed during the neutralizasolutiontherein astion step. 7

The following, considerations are applicable where the mixture. obtainedafter neutralization with the amine jisto bejformulated into a finalformulation adapted'to'b'e marketed for plant growth'regulating orweed-killing purposes. We prefer to formulate by dissolving theneutralized mixture in a suitable hydrocarbon oil to give "a stableconcentrate ready for marketing and capable uponaclmixturewith water oroil in the field oif giving a sprayingfemulsionor solution of a We"often incor satisfactory characteristic porate additional-surf'ace"active agent of any suitable type in making' theformulation} the reasonfor this is'that usually the amount of catalyst used is insufiicient toprovide, upon neu' tralization with the organic amine, the necessaryordesiredc'oncentrationbf surface active agent in the finishedformulation or in the final spray solution. "The amount of surfaceactive agent inshould be sufficient to prothe final formulation moterapid .emu'lsification and give a stable 6O ganic amine used toneutralizeth sulfonic acid.

emulsion having the when the: farmer or finished formulation with waterin the field or to give a solution having the desired surface active andwetting characteristics when the operator mixes it with oil in thefield. Those skilled in the art can readily select a suitable extraneoussurface active agent and determine the amount thereof required for thedesired results.

The oil' used in formulating generally comprises an oil 10f essentiallyparaflinic nature and of-petroleum origin and an oil of an aromaticnature. We can use any paraifinic oil of the proper mobility andviscosity. We prefer to use those oils which are typified by keroseneand naphthalsuch'as V. M. & P. naphtha or Stoddard solvent) "since thesere notsufliciently volatile to present an objectionable fire hazard andwhen the final spray composition is applied in the field theyevaporateat a sufiicintly low rate. We generally use a blend of aromaticand aliphatic I of chemicallyf combining with the catalyst to produce asurface the long chain desired wetting properties other. operator mixesthe oilszdfl'he: partieularnoilsizandamounts; cr mes-ch. used willclenendmponllthe iparticulamaryloxy .na d;.;a 1iphatic;.or: aromatic.hydrocarbon oils to give g;reat e r solubility and: also reduceflammabill-lay. Alcohols sandetherealcohols: arexsome-v times used insmaller; amounts----to,.givei greater sol bi-lity.

filer some thesessesters can 1 be used without the addition Bf-5amhydrocarbon .oil hand m t es withno iimther addition ofi su face. geester of 2,43 5

activeor. emu lsiityli ng/ agents. i For examplea the butyl ester. of2,4D,,-.prepared.ias in:;Examp'1e.,2, but. notformulated a as, inExample- -,2,. can be emulsified. directly. water .in an. agitatedsprayri g or diluted directly. in diesel oil)' for applicatio .as desired. iv the proper. combination .oilamine. and-base oils 1s usdftheestefandftheamine.saltof the long chain allgvl arylisi' lfo'nic acid.will be completely solublein the ester .ior'm'ulation' to' give stablesirigle-phasfe.,products.

The concentrate, i. e., "the' finished formulation, preferably containsat least 29% by wei'g'htbf aryloxyacetic f'aciifthis. acid being presentin cox'n'bined form 4, the ester. The concentration of 'aryloxyadetic accan range as? high as'T75'to 801%" of the"' 1 inal" ;mi-niu1etion and:can be even higherth'an' 180%" fwh eretno i'petro'l'eum base .611

isf llsed inftheforin'ulation e' fases desirable, to erificati'onreaction ss alaenoi andv entrainbe doneonly with arnines whichwould. not be. removed by h ubs t i d k ai a I r general .it ;is-.easier to achieve. nearly .completeesterification when:the;catalyst isused than i l r t 91? used-i :1 E 1 h s sea n ve ij of wi ulan .va enmin the morewwl ri mak be s. naddition, the" :use :01 the atalystsubstantiallyi overcomes ,the poisoni s-s es ..0f1= any orahic-icarrierwwhich may .be present in the: aryloxyaceticz racid. asarresultssof. the :use. of an iorganicicarrier; processs suchaas 21'sshownin-swarrenlllr szrPatent 2,480,817.

-.1lThe followingl wonkingxxamplesliillustrate "our mventionsin'greaterQ-detail: in-ll- :par-ts are by i EmampZeJ i Estrmcatie mixture;n-b'utanol"'250 24:13, 440.

NO. catalyst was; used. "The ingredients. were mixed and hat-ed vtoirefiux the vaporsbe'ing confinsde and; the condensate.collected;allowed to undergb' ==separation. intolzan. l upper. butanol-richlayer.- and. a lower substantially aqueous layer. Theiupper butanollayer'was returned to :the .re-a action mixture, .The; refiuinng. wascontinuedfor,

3. hours and 45 -minutesnwh'ereupon..the excess butanol was distilled.from the ester product under. greduced; .pressune. 541-. .parts oftechnical ri;-butyl-ester,.of 3A D were ebtained 1?his wastormuiatedasfoilowsz Kerosene 763 Esobu-tanol:=nabutariolz'EB: 1'. I

Sterox 0D '(pol'yoxyethylenee ester emulsi- 4420; Ker-ylvbenzenesulfonic acid 60,

.'I'he..-cata1yst was used; in an. amountequal pH: 5 by. the additionwof10 parts-isopmpylamin.

This was formulated. asfollows:

It is readily seen that the ior mulationlisidentical with that ofExample. 1, exce'ptthat 25. partsof the. commercial emulsifier .arereplaced by 12 parts isopropylammonium keryl benzene isulfonate. Thisformulation. gaveslightlysupe'rior emulsifying properties. 1

Example 3' Esterification mixture'z", glycero193, 2,4' D 66.0,

Keryl benzene sulfonic acid 20.

' /r-hour.

Example 4 55 minutes to aze-otropically removelthewateri' {The timetaken remove the water "of est erijf 55 i fication in A was 1h-our'"20.minutesiahd in 'Bwasj 33' minutes.

' Example b .Esterifi-cation mixture: Y. Polypropylene zzgliico i (molswt. 150) 930, 2,4-D 1320, Ker yi1benzene sule,

fonicacid 33, toluene 50.

The water .of reaction- -was removedin L hour;

minutes.

' Example 7 Water removed'in 2 hours 'ilillt'i-mi'nutes.

Example? acid .5.

minutes.

1 Time required for esteri ficationl Esterification mixture: an butanol25.0, s2, V 9-," 11%:gb-y weight oftheoreticalnester yield. ime,reaction was carried outias in the above Example. 15 1. f Refluxing wasiequiredior onlyfl-hours and '7.minutes. 600. parts oftechnicaln-butylester (Ester'ification .mixture :i isoprqpanol r 144,;-

Estei'iifi-cation mixturet iCelanesel selvent zllii 25-0; 254+!) 4 ry-lbenzene Sin-01110; acidliiln 1 Example 9 Esterification mixture:Butoxyethanol 240, 2,4,5-1 510, Keryl benzene sulfonic acid 5, toluene50. l

Water w-asremoved upon heating for 3 hours 35 minutes.

In each of Examples 3 to 9 an organic amine was added to the mixture ofester and catalyst at the time of formulation to form the amine salt ofthe catalyst in situ. Additional typical formulations follow:

Example 10 Formulation:

Butoxyethyl ester of 2,4-D (containing catalyst) from Example .55

Polyoxyethylene ester-type emulsifier- 3 Shell Oil TS-28 (aromaticnaphtha; Sp. Gr. 0845-0865; 75% aromatics; .mixed anilinepoint, 90 F.,B. R.,

Isopropylamine 0.17

Example 11 Example 12 Esterification mixture: V

n-Butyl carbinol 60 2.4-1) 110 Keryl toluene sulfonic acid 2 The mixturewas refluxed for one hour and the water formed removed in the same wayas in Example 1. The mixture was subsequently vacuum stripped to removeunreacted alcohol.

The ester obtained was formulated as follows:

to give a water-emulsifiable concentrate.

Example 13 Esterification mixture:

Isooctyl alcohol l 50 2-methyl-i-chlorophenoxyacetic acid 50 Keryltoluene sulfonic acid 1 The mixture was refluxed and the water re--moved in one-half hour.

The ester was formulated as follows:

Isooctyl ester of 2-methyl-4-chlorophenoxyacetic acid .15 ShellTS-28solvent 14 Polyoxyethylene ester type emulsifier "1 Triethanolamine 0.05Butyl Cellosolve solvent (mono n Butyl ether of ethylene glycol) 1Example 14 Esterification mixture:

em to those skilled in the art.

advantages, the following may be enumerated.

Lorol No. 5 (Du Pont commercial lauryl The water of reaction was removedazeotropically by refluxing for one hour. The benzene and excess alcoholwere then removed by vacuum stripping.

The ester product was formulated as follows:

Lauryl ester of beta-naphthoxy acetic acid 10.0 Toluene 20.0Polyoxyethylene ester type emulsifier 1.0

Armeen C (mixture of higher primary aliphatic amines obtained fromhigher fatty acid mixture) 0.05

Example 15 Esterification mixture:

n-Butyl carbinol 35.0 Beta-naphthoxy acetic acid 36.0 Keryl toluenesulfonic acid 1.0

The water of reaction was removed in 1 /2 hours. The ester wasformulatedas follows:

n-Butyl carbinol ester of beta-naphthoxy acetic acid 4. 10.0 Toluene 5.0Polyoxyethylene ester type emulsifier 1.0 Triethylamine 0.05

From the foregoing description, many advantages of the present inventionwill be appar- Among these The invention provides an extremely activeyet mild catalyst'for the esterification, comparable tosulfuric acid inactivity yet mild in that it eliminates the objectionable decompositionof the ester and more especially of the alcohol by sulfuric acid; theester is extremely stable in the presence of the long chain alkyl arylsulfonic acid of the present invention whereas itwas often objectionablyunstable in the presence of the sulfuric acid heretofore used. Thepresent invention is further highly advantageous in that it completelyobviates the necessity of removing the catalyst after the esterificationreaction. The present invention is especially advantageous in thatinstead of removingthe catalyst we convert it directly andquantitatively to an excellent emulsifying, wetting, dispersing andsurface acing subsequent formulation and during subsequent admixturewith water, oil or other materials preparatory to use of theformulation. Thus,

the present invention avoids the cost difficulty incidental to removalof the catalyst and at the same time utilizes the long chain alkyl arylsulfonic acid in a dual role, namely as catalyst and later, afterconversion to the amine salt, as a "built-in, highly efiicacious surfaceactive and like agent. The invention also avoids any neces- 1 sity forwashing the ester with water after neuadvantages of ourinvention willmore fully hereinafte'r appear.

Having thus described our invention, what we 11 claim and desire toprotect by Letters Patent is: 1. In the process of makingv a compositionof matter. containingv an ester. of an aryloxyacetic 1 acid, the stepswhich comprise reactingv an aryloxyacetic acid with an. alcoholin thepresence of an alkyl-substituted aryl sulfonic acid, inwhich the alkylside chain contains at least ten carbon atoms, as an esterificationcatalyst until esterification of said acid with said alcohol issubstantially completethereafter neutralizing said alkyl-- substitutedaryl sulfonic" acid'wit-h an organic amine, and thereby forming in situan amine salt of said alkyl-substituted aryl sulfonic acidwhichis:.available.asra surface active and; like agentzwhen theresultingmixture is used.

2.,In theprocess of making a ,compositioniof matter, containing anester: of -anyaryloxyacetic acid, the steps which compriseireacting, anaryloxyacetic acid'with an alcohol 'in'the presence of a keryl arylsulfonic acid asanvesterification catalyst until esterification of saidacid with said alcohol is substantially complete, thereafterneutralizing said keryl aryl sulfonic acid .with an organic amine, andthereby, formingin situ an amine salt'of said'keryl aryl sulfonic acidwhich is available as a. surface active and. like. agent when theresulting mixture is used.

acid, neutralizing saidalkyl-substituted arylsul- V ionic acid with anorganic amine and thereby forming; in situ an amine salt of said.alkyl-sub stituted aryl sulfonic acid, formulating the resultingmixture into a finished formulation by. dissolving it in oilto asuitable concentration, and

thereby obtaining a, formulation in which said amine's altof saidalkylw'substituted aryl sulfonic acid is available as a surface activeand like agent when said.'formulation is used.

'8'. In the process of making-a composition of matter containing anester 'of' an aryloxyacetic acid as the active ingredient, the stepswhich comprise reacting an aryloxyacetic acid withan alcohol in thepresence of a kery-l' aryl'sul'fonic acid, :as an esterificationcatalyst until esterification of said acid with said alcohol issubstantially complete," recovering fromthe esterification reactionmixture a material consisting essentially of the" ester produced andsaid keryl aryl sulfonic: acid, neutralizing said keryl aryl sulfonicacid with an organicamine and there- "by forming in situ an amine saltof said keryl 3. A. process as set forth in claim. 2 wherein saidsulfonic acid is keryl benzene su'lfonicfacid.

4. A process as set forth in claim 2 wherein said sulfonic acid is keryltoluene sulfonic. acid. 5. In the process of making a composition ofmatter containing [an ester of, an. v.aryloxyacetic acid'as the activeingredient, the steps which comprise reacting an aryloxyacetic acid withan alcohol in the presence of an alkyl-substituted aryl sulfonic acid,in which the. alkyl side chain contains at least ten carbon atoms, as anesterification catalyst, in an amount ranging from 0.25

to 15% by weight based on the weight of ester theoretically to beproduced, until esterification of said acid with said alcohol issubstantially complete, thereafter neutralizing said alkyl-substitutedaryl sulfonic acid with an organic amine, and thereby forming in situ anamine salt of said alkyl-substituted aryl sulfonic acid which is available as a surface active and like agent when'th amine, and therebyforming in situ an amine salt of said keryl aryl sulfonic acid which isavailable as asurface active and like agent when theresulting mixture isused.

7. In the process of making a composition. of matter containing:an'ester of an aryloxyacetic acid as the active ingredient, the stepswhich comprise reacting an aryloxyacetic acid withan alcohol in thepresence of an alkyl-substituted arylsulfonic acid, in which. the alkylside chain. contains at leastten carbon atoms, as an esterificationcatalyst until esterification of said acid I with said. alcohol issubstantially complete, re-

covering from. the esterification reaction mixture a material consistingessentiallyof the'ester produced and said. ;alkyl-substituted; arylsulfonic? aryl sulfonic acid, formulating the resulting mixture into afinished formulation by dissolving it in oil to a suitableconcentration, and thereby obtaining a: formulation in which said. aminesalt of saidikeryl: aryl=sulfonic acid isavailable as a surface activeand like agent when said final formulation is used.v

9-.A.process.as set forthin claim 8 wherein said. sulfonic acid isemployed in'an amount ranging from 0.25- to 15 by weight based on thematter acid as the active ingredient, the steps which comprise reacting2,4-dichlorophenoxyacetic acid weightiof ester theoretically to beproduced.

10. In the process of making a composition of containing2A-dichlorophenoxyacetic with an alcohol in the presence of a kerylarylsulfonic acid as an esterification catalystv in an amount ranging from0.25 to 15% by weight based on the weightof ester theoretically'to beproduced, employing a molecular excess of said alcohol over said2,4-dichlorophenoxyacetic acid,

continuing said reaction until esterification of said2,4-dichlorophenoxyacetic acid with said alcohol is substantiallycomplete, removing the excess alcohol from the resulting mixture andrecovering a mixture consisting essentially of the ester productandxsaid keryl aryl sulfonic acid, thereafter neutralizing said kerylaryl sulfonic acid with an'organic amine and thereby forming I in situan amine salt of said keryl aryl sulfonic acid which serves as a surfaceactive and like agent when the resulting mixture is used.

' 11. A process as set forth in claim 10 wherein said sulfonic acid .iskeryl benzene sulfonic acid.

12. A process as set. forth in claim 10 wherein said sulfonic acid iskeryl toluene sulfonic acid.

13. In the process of making a composition of I matter containing2,4,5-trichlorophenoxyacetic acid as the active ingredient, the stepswhich comprise reacting 2,4,5-trichlorophenoxyacetic acid-.withanalcohol in the presence of a keryl aryl sulfonic acid as anesterification catalyst in I an amount ranging. from 0.25 to. 15% byweight based on the Weight of ester theoretically to beproducedyemploying a molecular excess of said alcohol over" said'2,4,5-trichlorophenoxyacetic acid, continuing said reaction untilesterification of said 2,4,5-trichlorophenoxyacetic acid with'saidalcohol is substantially complete, removing the excess alcohol fromthe resulting mixture recoveringa mixture consisting essentially JOHN C.R. WARREN. FREDERICK M. M. J. HAGER.

14 REFERENCES CITED The following references are of record in the fileof this patent:

UNITED STATES PATENTS Number Name Date 2,314,255 Toone Mar. 16, 19432,390,941 Jones Dec. ll, 1945

1. IN THE PROCESS OF MAKING A COMPOSITION OF MATTER CONTAINING AN ESTEROF AN ARYLOXYACETIC ACID, THE STEPS WHICH COMPRISE REACTING ANARYLOXYACETIC ACID WITH AN ALCOHOL IN THE PRESENCE OF ANALKYL-SUBSTITUTED ARYL SULFONIC ACID, IN WHICH THE ALKYL SIDE CHAINCONTAINS AT LEAST TEN CARBON ATOMS, AS AN ESTERIFICATION CATALYST UNTILESTERIFICATION OF SAID ACID WITH SAID ALCOHOL IS SUBSTANTIALLY COMPLETE,THEREAFTER NEUTRALIZING SAID ALKYLSUBSTITUTED ARYL SULFONIC ACID WITH ANORGANIC AMINE, AND THEREBY FORMING IN SITU AN AMINE SALT OF SAIDALKYL-SUBSTITUTED ARYL SULFONIC ACID WHICH IS AVAILABLE AS A SURFACEACTIVE AND LIKE AGNET WHEN THE RESULTING MIXTURE IS USED.